Lob may change the Mailpiece Fees upon 15-days prior written notice (“Mailpiece Fee Increase”) (email is sufficient). Provided however, that any such Mailpiece Fee Increase shall occur not more than twice per year and no more than once per quarter. The amount of the Mailpiece Fee Increase shall be no more than 40% of the amount of the percentage increase in the most recently published Consumer Price Index (“CPI”) and 60% of The Producer Price Index: Pulp, Paper, and Allied Products (“PPI”) as published respectively by the Bureau of Labor and Statistics (or its successors) and the St. Louis Federal Reserve . The Mailpiece Fee Increase, if any, shall be effective at the end of the aforementioned 15-day notice period. CPI means the Consumer Price Index for All Urban Consumers, All Items, All Cities, issued by the Bureau of Labor Statistics of the United States Department of Labor (1982-184=100). PPI means The Producer Price Index: Pulp, Paper, and Allied Products, issued by the St. Louis Federal Reserve (1982=100). Notwithstanding the foregoing, Lob may increase Mailpiece Fees due to a change in USPS postage rates at any time upon fifteen (15) days prior written notice to Customer (email is sufficient).